1. Field of the Invention
The present invention relates generally to casing valves for use in well bores, to positioning tools for positioning a sliding member in a casing valve and jetting tools for washing a casing bore by spraying fluid through a port in the casing valve. More particularly, the invention relates to a casing valve with a relatively short stroke incorporating a selective latch profile engageable by a positioning tool which is adapted to prevent hangup of the positioning tool in other locations in the casing string. In one embodiment, a non-rotating jetting tool is used.
2. Brief Description of the Prior Art
It is known that sliding sleeve type casing valves can be placed in the casing of a well to provide selective communication between the casing bore and subsurface formation adjacent to the casing valve. One such casing valve is shown in U.S. Pat. No. 4,991,654 to Brandell et al., assigned to the assignee of the present invention. The casing valve includes an outer housing with a sliding sleeve. First and second seals define a sealed annulus within the housing. A latch is disposed in the sealed annulus for latching the sliding valve in its first and second positions. The housing has a plurality of housing ports defined therein, and the sliding sleeve has a plurality of sleeve ports defined therein. A third seal disposed between the sleeve and housing isolates all of the housing ports from all of the sleeve ports when the sleeve is in its first position relative to the housing. When the sleeve is moved to its second position relative to the housing it is aligned so that the sleeve ports are in registry with the housing ports. This alignment is achieved by a lug and groove which are also disposed in the sealed annulus of the casing valve.
The sleeve in the casing valve of Brandell et al. is positioned by the positioning tool disclosed in U.S. Pat. No. 4,979,561 to Szarka, assigned to the assignee of the present invention. The positioning tool includes a drag assembly having a longitudinal passageway defined therethrough. An inner mandrel is disposed through the longitudinal passageway of the drag assembly and is longitudinally movable relative to the drag assembly. An operating assembly is provided for selectively operatingly engaging the sliding member in the casing valve in response to longitudinal reciprocating motion of the inner mandrel relative to the drag assembly.
Once the sliding sleeve in the casing valve is moved to its second position, fluid may be jetted through the jetting tool of Szarka et al. disclosed in U.S. Pat. No. 5,029,644, also assigned to the assignee of the present invention. The jetting tool is connected at a rotatable connection to the positioning tool. The jetting tool is thus rotatable relative to the positioning tool and the casing valve. The jetting tool hydraulically jets the casing valve as the jetting tool is rotated relative thereto.
The casing valve of Brandell et al. was designed to have a relatively short stroke compared to some prior art valves at that time. However, it is desirable to even further shorten the stroke of such valves. The present invention provides a casing valve with an even shorter stroke.
In some instances, it is possible that the prior art positioning tool can hang up in the casing string by inadvertently engaging recesses which exist in the casing string. Also, some auxiliary tools, such as retrievable bridge plugs have portions thereof, such as drag blocks, which may fall into the long gap of the sliding sleeve in prior casing valves and hang up therein. Any of these hangups can cause damage to the positioning tool, casing valve and/or auxiliary tools.
Accordingly, there is a need to prevent such hangups, and the present invention solves this problem by providing a sliding sleeve in the casing valve with a selective latch profile, and the positioning tool has a positioner block with a corresponding selective latch profile so that the positioner block will latch only in the profile in the casing valve and not engage anything else in the casing string.
A further possible problem with prior art tools of this type is that in small bores, it may be difficult to provide jetting tools which are rotatable. The present invention solves this problem by providing one embodiment with a jetting tool utilizing a plurality of jets such that at least one of the jets is substantially aligned with the ports in the casing valve regardless of the angular relationship between the jetting to and casing valve.